Shelf mounting and securing means



12, 1963 A. R. CQSTANTINI ETAL 3,110,536

SHELF MOUNTING AND SECURING MEANS 2 Sheets-Sheet 1 Filed May 14, 1962 ||Il I III 'll II ATTOR EY Nov. 12, 1963 A. R. COSTANTlNl ETAL 3,110,536

SHELF MOUNTING AND SECURING MEANS 2 Sheets-Sheet 2 Filed May 14, 1962 NVENTORS 33a ANTHONY R COSTANTINI F g 8 ANTHONY 0| ANGELUS ATTORNEY United States Patent SHELF MOUNTING AND SECURING MEANS Anthony R. Costantini, Philadelphia, and Anthony Di Angelns, Manoa, Pa., assignors to Victory Metal Mann.- facturing Company, doing businesses Victory Metal Manufacturing Corporation, Plymouth Meeting, Pan,

a corporation of Pennsylvania Filed May .14, 1962, Ser. No. 194,447 12 Claims. (Cl. 312-350) This invention relates generally to cabinet constructions, and more particularly relates to cabinets of the type that are provided with removable shelves and vertically adjustable shelf supporting means for adjusting as desired the height of individual shelves within the cabinet, as for example illustrated by refrigerating cabinets.

In the past, refrigerating cabinets have been made with pilaster structures to which could be attached shelf supporting rails which were either permanently secured in position as by means of screws or bolts or which were loosely hooked into place for easy attachment and detachment to facilitate positionally adjusting the same. The securely mounted siderails offer the advantage of mechanical stability, but are disadvantageous in that initial installation and subsequent position changing of such rails is a relatively time consuming process. The loosely hooked type of siderail while readily attachable and detachable for position shifting is characterized by mechanical instability and non-rigidity due to the generally loose type of coupling between the siderails and the supporting members. The present invention combines the mechanical stability and rigidity of the permanently secured type of siderail structure with the ease of securement and attachment characteristic of the hook-engaged type of siderail while avoiding the undesirable characteristics of each, Accordingly, it is a primary object of this invention to provide a novel siderail support structure for cabinet held shelves and trays which is quickly and easily securable in operative position and similarly detachable for shifting to a different desired support position.

- Another object of this invention is to provide a novel shelf and tray supporting structure, for use within the interior of cabinets, which includes a novel type of pilaster support combined with a novel siderail having elements interlockable with the pilaster to provide a rigid structure which must be positively engaged with and detached from the pilaster, and which cannot free itself of its own action.

Still another object of this invention is to provide a novel shelf supporting structure for use within the interior of cabinets, as aforesaid, in which the shelf supporting siderails are placed in torsion while being interlocked with and detached from their associated supporting pilasters.

The foregoing and other objects of the invention will become clear from a reading of the following specification in conjunction with an examination of the appended drawings, wherein:

FIGURE 1 illustrates in perspective view a refrigerator cabinet having a plurality of pilaster strips secured to the inside wall liners of the compartments, and a plurality of siderails interlockingly engaged with the pilasters, all

in accordance with the invention;

FIGURE 2 is a vertical sectional view through the right-hand refrigerator compartment of FIGURE 1 illustrated with the compartment door closed and more clearly showing the organization of one of the siderails interengaged with and extending from front to rear between the vertically extending pilasters secured to the sidewall liners;

FIGURE 3 is an enlarged fragmentary front elevational view of the pil-asters illustrated in FIGURES 1 and 2 to most clearly show the novel pilaster aperture shape; i

FIGURE 4 is a perspective view of the novel siderail structures employed in conjunction with the novel pilaster of FIGURE 3, the pair of siderails illustrated being mirror images of one another and corresponding to the lefthand and righthand rails of a pairas would be utilized for a shelf or tray support;

FIGURE 5 is an enlarged fragmentary view of the left hand end section of the rear one of the pair of siderails illustrated in FIGURE 4;

FIGURE 6 illustrates in perspective form one of the novel siderails of FIGURE 4 in installed secured posi-v tion interlocked with a pair of the novel pilasters, all as shown in solid line, and a superimposed phantom view of the novel siderail shown in partially installed position with the pilasters;

FIGURE 7 is an enlarged front elevational view of the novel siderail in installed position on the pilasters according to the invention;

FIGURE 8 is an enlarged fragmentary view shown partly in section and partly in top plan through the rear end of the installed siderail, as would be seen when viewed along the line 8--8 of FIGURE 7;

FIGURES 9, 10 and 11 are vertical sectional views through the forward end of the novel siderail and its associated pilaster illustrating successive steps for positioning and inter-locking the front end of the siderail with the pilaster, these three positioning steps illustrated being associated with the forward end of the siderail shown in phantom line in FIGURE 6.

In the several figures, like reference characters.

In FIGURES l and 2 there will be seen a refrigerator cabinet designated generally as 20 having a pair of sideby-side compartments 2d and '22 including sidewall liners 23 to which are secured 'vertically extending pilasters 24 adapted to carry tray or rack supporting siderails 25. The lefthand compartment 21 in FIGURE 1 is illustrated with a tray 26 disposed therewithin and slidably supported by a pair of the siderails. As best seen in the showing of FIGURE 2, the pilasters 24 are disposed proximate the front and rear of the sidewall liner 23 within the compartment, and the siderail 25 is seen to extend from front to rear within the compartment, extending between and intenlocked to the p-ilasters 24.

As best seen in FIGURES 3 and 8, the pilaster-s 24 are of generally U-shaped cross-section having a front wall 27 land a pair of rearwardly extending sidewalls 28. The front wall 27 is provided with a series of equally spaced and longitudinally aligned apertures punched therethrou-gh, each of the apertures having a square hole portion 29 and a narrow slot 30 extending lengthwise of the pilaster from the center of the top edge of the square hole 29, the slots 30 being of narrower width than the length of the hole side and all being in longitudinal alignment lengthwise of the pilaster.

As best seen in FIGURES 4 and 5, the siderails generally designate-d as 25 are seen to be a mirror image .pair designated in FIGURE 4 as 25a and 25b, each siderail being of generally U-shaped cross-section and respectively including vertically extending main walls 31a and 31b, horizontally extending top walls 32a and 32b and horizontally extending bottom walls 33a: and 33b. Punched through and turned laterally outward from the vertical walls 31a and 31b of the siderails and projecting rearward in a common plane laterally ofiset from the plane of the vertical walls are a pair of hook elements designated 34a and 34b. The vertical height of each of the hook elements is somewhat less than the vertical extent of each of the square holes 29 punched elements are denoted by like through the pilasters 24, and the center to center vertical distance between the hooks is the same as the center to center vertical distance between any two adjacent square holes 29 in the pilasters 24, so that these hooks may be projected laterally into any such adjacent pair of pilaster holes, as best seen in FIGURE 8 wherein it Will also be observed that the lateral offset of the hooks from the plane of the siderails vertical wall is equal to the thickness of the pilaster front wall 27. Additionally, the length of each hook is somewhat less than the distance between the inside surface of a pilaster side wall 2% and the near edge of the square hole 29, and is also substantially the same in length as the width of the pilaster square holes 29 so that the hooks may be readily projected through the square holes and locked behind the pilaster front wall 27 by end shifting of the entire siderail.

Punched out of the vertical and bottom walls of each of the siderails 25a and 2512 at the fore end thereof and turned laterally outward and downward into plane with the rear hooks 34m and 34b are the downwardly projecting hooks 35a and 35b. The width of the hooks 35a and 35b is slightly less than the width of the square pilaster holes 29 so that these hooks may be projected through the holes, and similarly the length of each of the hooks is slightly less than the height of each of the pilaster holes 29. Also at the fore end of each of the siderails 125a and 25b are located the locking tongues 36m and 36b punched out of the vertical wall and top wall of each of the siderails and turned laterally outward therefrom into a plane substantially perpendicular thereto which vertically bisects the downwardly extending front hooks 35a and 35b.

The tongues 36a. and 3617 are of generally rectangular shape with the long side oriented vertically and having the lower outer corner cut away to provide a smoothly rounded curved edge at the lower rear edge of the tongues. As is most clearly seen in FIGURES 9, l0 and 11, each of the tongues is joined to the vertical wall of its siderail by an in-plane bridge 38a or 38b which is integral with the tongue and vertical wall, the bridge portion being recessed upward from the bottom to form a catch'at the bottom of the tongue along the side closest to the siderail vertical wall, the catch being designated in FIGURES 9 through 11 as 39a. The tongues also extend vertically upward above the tops of the bridges 38 and siderails topwalls 32 as designated at 49a and 40b, and these tongue upper sections are cut back so that the vertically extending edges thereof which lie closest to the siderail topwalls are laterally olfset from the siderail vertical wall by an amount equal to the thickness of the pilaster front wall 27, the illustrated tongue lower catch 39a being similarly offset.

Installation of the siderails 25 is illustrated in the showings of FIGURES 6 through 11, attention being first directed to FIGURES 6, 7 and :8 which illustrate the installation of a lefthand siderail 25a. The first step in installation is that of inserting the rear hooks 34m into a pair of adjacent square holes 29 of the rear pilasterv 24 secured within a cabinet, and then rcarwardly endwise shifting the siderail 25 to lock the hooks behind the pilaster front wall 27 in the manner seen in FIG- URE 8 so that the vertical wall 3-1 of the siderail is pressed firmly flatwise against the outer surface of the pilaster front wall 27. The siderail 25a is shown in this partially secured position by the phantom line showing of FIGURE 6.

The front end of the siderail 25a is next grasped and twisted in counter-clockwise direction, as shown by the arrow 41 of FIGURE 6-, and moved inward to the front pilaster 24, as shown by the arrow 42, until the upper section 40a of the tongue 36a: is projected through the slot 30 and square hole 29 which is at the same horizontal elevation as the square hole 29 through which the upper one of the rear hooks 34a is projected in the rear pilaster 24. The siderail so disposed is illustrated in the showing of FIGURE 9. The torsional force being exerted on the siderail is now released to allow the front end of the siderail to straighten out into alignment with the rear end and permit the downturned front hook 35a. to move inward through the pilaster square hole 29 as shown by the arrows 43 in FIG- URE 9. The curved bottom edge 37a of the tongue 36a permits this motion to take place when the upper edge of the bridge 38a is seated against the top of the pilaster slot 30, the'interfitted position of the siderail ront end with the pilaster being shown in FIGURE 10. Finally, the fore end of the siderail is pressed downward so that the downturned hook 35a and the tongue catch 39a: lock foehind the front wall 27 of the pilaster 24. The tongue upper portion 46a also remains disposed behind the pilaster front wall 27, extending above the top of the associated pilaster slot 3% The siderail 25b is of course installed in precisely the same manner, and the siderails are quickly and easily removable by merely reversing the aforedescribed installation procedure.

From the foregoing description and the drawings, it will be appreciated that the slderails are securely firmly locked to the pilasters and are completely immovable in any horizontal direction. Additionally, the siderails are immovable at their rear end in a vertical direction, and while the fore end is vertically shiftable it cannot be detached by being so shifted. The only way in which the siderail may be detached is by first vertically shifting the fore end to its upper limit of travel and by then applying a positive torsional force to twist the lower hook 35 out of the pilaster before dropping the tongue upper section out of its associated slot 30 and hole 29. Such a procedure cannot inadvertently occur and can take place only as the result of a deliberately directed detachment force because in general the siderails are formed from a reasonably heavy gauge metal such as stainless steel.

Having now described our invention in connection with a particularly illustrated embodiment thereof, it will be understood that modifications and variations of the same may now occur from time to time to thosepersons normally skilled in the art Without departing from the essential scope or spirit of the invention, and accordingly it is intended to claim the same broadly as well as specifically as indicated by the appended claims.

What is claimed as new and useful is:

1. A siderail for supporting a tray within a cabinet at a desired elevation by securement of the siderail to a pair of parallel spaced apart vertically extending pilasters having apertures formed therethrough at regularly spaced intervals along the pilaster length, said siderail comprising, a horizontally longitudinally extending main wall disposed in a substantially vertical plane, a tray support element secured to said siderail main wall and projecting laterally to one side of the plane of said siderail main Wall, at least one hook element extending from said side rail main wall proximate to and forward of the rear end thereof, said hook element pointing rearward and being disposed in a plane laterally offset from and substantially parallel to the plane of the main wall, another hook element extending from said siderail main wall proximate to and rearward of the fore end thereof, said another hook element pointing downward and being disposed in a plane laterally offset from and substantially parallel to the plane of the main wall, and a tongue element extending from said siderail main wall in the region of said another hook element and lying in a plane substantially perpendicular to the plane of the main wall, said siderail being adapted for locking engagement to said pair of pilasters by first engaging said at least one hook with one of the pilasters through one of the apertures thereof and locking the hook to the pilaster by end shifting the siderail, torsioning the siderail fore end to project the said tongue element through an aperture of the other pilaster and upward therebeyond, projecting the said another hook through a lower aperture in the other pilaster by releasing the torsion on the siderail fore end, and then depressing the fore end of the siderail.

2. Apparatus for supporting a tray or shelf within a cabinet at a desired elevation, comprising in combination, a pair of parallel spaced-apart vertically extending pilasters adapted for securement to the cabinet wall and-having apertures formed through the pilaster front :wall at regularly spaced intervals along the vertical length thereof, and a horizontally extending siderail lockable at its front and rear ends respectively to a different one of said pair of pilasters by front and rear locking means associated with said siderail, said rear locking means including a projection engageable with one of said pair of pilasters through a front wall aperture thereof and lockable to said pilaster so engaged by shifting said siderail longitudinally endwise, said front locking means including a pair of projections engageable with the other of said pair of pilasters respectively through a pair of front wall apertures thereof and lock-able to said pilaster so engaged by (a) first rotating the said siderail about its longitudinal axis and inserting one of said pair of projections through one of said pair of pilaster front wall apertures to thereby dispose the same partially behind the pilaster front wall,

(b) then counter-rotating the said siderail about its longitudinal axis and inserting the other of said pair of projections through the other of said pair of pilaster front wall apertures,

(c) and vertically shifting'the siderail front end to lock said pair of projections to the pilaster with .which they are engaged.

3. The apparatus according to claim 2 wherein said siderail rear locking means projection includes a rear wardly turned hook element extending from the body of the siderail proximate the rear end thereof disposed in laterally offset parallel relation to the longitudinal extent of the side rail, said hook element passing closely behind a portion of the pilaster front wall when the side rail is longitudinally endwise shifted to thereby position the said hook element and siderail body closely adjacent to and on opposite sides of the said pilaster front wall portion.

4. The apparatus according to claim 2 wherein said siderail front locking means pair of projections respectively include a downwardly turned hook element extending from the body of the siderail proximate the front end thereof disposed in laterally offset parallel relation to the longitudinal extent of the siderail and a vertically turned tongue element extending from the body of the siderail proximate the front end thereof disposed in laterally oifset relation to the body of the siderail and in vertically offset relation to the said downwardly turned hook element, said downwardly turned hook element and vetically turned tongue element passing closely behind different portions of the pilaster front wall when the siderail front end is vertically downwardly shifted.

5. A siderail for supporting a tray within a cabinet at a desired elevation by securement of the siderail to a pair of parallel spaced apart vertically extending pilasters having apertures formed therethrough at regularly spaced intervals along the pilaster length, said siderail comprising, a horizontally longitudinally extending main wall disposed in a substantially vertical plane, a tray support element secured to said siderail main wall and projecting laterally to one side of the plane of said siderail main wall, at least one hook element extending from said siderail main wall proximate to and forward of the rear end thereof, said hook element pointing rearward and being disposed in a plane laterally offset from and substantially parallel to the plane of the main wall, another hook element extending from said siderail main wall proximate to and rearward of the fore end thereof, said another hook element pointing downward and being disposed in a 6 plane laterally offset from and substantially parallel to the plane of the main wall, and a tongue element extending from said siderail main wall in vertically offset abovelying relation to said another hook element and lying in a plane substantially perpendicular to the plane of the main wall, said siderail being adapted for. locking engagement to said pair of pilasters by first engaging said at least one hook with one of the pilasters through one of the apertures thereof and locking the hook to the pilaster by end shifting the siderail, torsioning the siderail fore end to project the said tongue element through an aperture of the other pilaster and upward therebyond, projecting the said another hook through a lower aperture in the a other pilaster by releasing the torsion on the siderail fore end, and then depressing the fore end of the siderail.

6. A siderail for supporting a tray within a cabinet at a desired elevation by securement of the siderail to a pair of parallel spaced apart vertically extending pilasters having apertures formed therethrough at regularly spaced intervals along the pilaster length, said siderail comprising, a horizontally longitudinally extending main wall disposed in a substantially vertical plane, a tray support element secured to said siderail main wall and projecting,

laterally to one side of the plane of said siderail main wall, a pair of hook elements extending from said siderail main wall proximate to and forward of the rear end thereof, said pair of hook elements both pointing rearward and being disposed vertically of one another in a common plane laterally offset from the plane of said siderail main wall, another hook element extending from said siderail main wall proximate to and rearward of the fore end thereof, said another hook element pointing downward and being disposed in the same common plane Y with the aforesaid pair of hook elements which are laterally offset from and substantially parallel to the plane of the main wall, and atongue element extending from said siderail main Wall in vertically offset above-lying relation to said another hook element and lying in a plane substantially perpendicular to the plane of the main wall, said siderail being adapted for locking engagement to said pair of pilasters by first engaging said pair of hook elements with one of the pilasters through a pair of the apertures thereof and locking the pair of hook elements to the pilaster by end shifting the siderail, torsioning the siderail fore end to project the said tongue element through an aperture of the other pilaster and upward therebeyond, projecting the said another hook through a lower aperture in the other pilaster by releasing the torsion on the siderail fore end, and then depressing the fore end of the siderail.

7. A siderail for supporting a tray within a cabinet at a desired elevation by securement of the siderail to a pair of parallel spaced apart vertically extending pilasters having apertures formed therethrough at regularly spaced intervals along the pilaster length, said siderail comprising, a horizontally longitudinally extending main wall disposed in a substantially vertical plane, a tray support element secured to said siderail main wall and projecting laterally to one side of the plane of said siderail main wall, at least one hook element extending from said siderail main wall proximate to and forward of the rear end thereof, said hook element pointing rearward and 'being disposed in a plane laterally ofli'set from and substantially parallel to the plane of the main wall, another hook element extending from said siderail main wall proximate to and rearward of the fore end thereof, said another hook element pointing downward and being disposed in a plane laterally offset from and substantially parallel to the plane of the main wall, and a tongue element extending from said siderail main wall in vertically offset above-lying relation to said another hook element and lying in a plane substantially perpendicular to the plane of the main wall, the plane of said tongue element substantially vertically bisecting said another hook element, said siderail being adapted for locking engagement 7 to said pair of pilasters by first engaging said at least one hook with one of the pilasters through one of the apertures thereof and locking the hook to the pilaster by end shifting the siderail, torsioning the siderail fore end to project the said tongue element through an aperture of the other pilaster and upward therebeyond, projecting the said another hook through a lower aperturein the other pilaster by releasing the torsion on the siderail fore end, and then depressing the fore end of the siderail.

8. A siderail for supporting a tray within a cabinet at a desired elevation by securement of the siderail to a pair of parallel spaced apart vertically extending pilasters having apertures formed thereth-rough at regularly spaced intervals along the pilaster length, said siderail comprising, a horizontally longitudinally extending main wall disposed in a substantially vertical plane, a tray support element secured to said siderail main wall and projecting laterally to one side of the plane of said siderail main wall, a pair of hook elements extending from said siderail main wall proximate to and forward of the rear end thereof, said pair of hook elements both pointing rearward and being disposed vertically in line with one another in a common plane laterally offset from the plane of said siderail main wall, the center-to-center vertical distance between said pair of rearwardly pointing hook elements being the same as the center-to-center distance between an adjacent pair of the pilaster apertures, another hook element extending from said siderail main wall proximate to and rearward of the fore end thereof, said another hook element pointing downward and being disposed in the same common plane with the aforesaid pair of hook elements which are laterally olfset from and substantially parallel to the plane of the main wall, and a tongue element extending from said siderail main wall in vertically offset above-lying relation to said another hook element and lying in a plane substantially perpendicular to the plane of the main wall, the plane of said tongue element substantially vertically bisecting said another hook element, said siderail being adapted for locking engagement to said pair of pilasters by first engaging said pair of hook elements with one of the pilasters through a pair of the apertures thereof and locking the pair of hook elements to the pilaster by end shifting the siderail, torsioning the side-rail fore end to project the said tongue element through an aperture of the other pilaster and upward therebeyond, projecting the said another hook through a lower aperture in the other pilaster by releasing the torsion on the siderail fore end, and then depressing the fore end of the siderail.

9. The apparatus according to claim 8 wherein the lateral ofiset of said pair of rearwardly turned hook elements from said siderail main wall is substantially equal to the thickness of the apertured pilaster wall through which said pair of hooks are projectable so that said pair of rearwardly turned hook elements pass closely behind a portion of the pilaster wall adjacent to the apertures therein when the siderail is end shifted to thereby position said pair of book elements and siderail body closely adjacent to and on opposite sides of the said pilaster wall portion. 7

10. Apparatus for supporting a tray or shelf within a cabinet at a desired elevation, comprising in combination, a pair of parallel spaced-apart vertically extending pilasters adapted for securernent to the cabinet wall and having substantially identical vertically aligned and identically oriented apertures formed through the front wall of the pilasters at regularly spaced intervals along the length thereof and also including stand-off means to space the rear face of the pilasters front wall away from the cabinet wall to provide a space therebetween when said pilasters are secured to the cabinet wall, the pilasters front wall apertures being generally rectangular and bounded by horizontal and vertical pairs of edgesof the pilasters front wall and including a slot through the pilasters front wall extending centrally upward from the upper horizontal bounding edge of each aperture to a point below the lower horizontal bounding edge of the next above-lying aperture, a siderail adapted for horizontal disposition between and securement to said pair of pilasters including, a horizontally longitudinally extending main wall disposed in a substantially vertical plane, a tray support element secured to said siderail main wall and projecting laterally to oneside of the plane of said siderail main wall, a pair of hook elements extending from said siedrail main wall proximate to and forward of the rear end thereof, said pair of hook elements both pointing rearward and being disposed vertically in line with one another in a common plane laterally offset from the plane of said siderail main wall and with the center-to-center vertical distance between said pair of hook elements being the same as the center-to-center distance between the rectangular portions of an adjacent pair of the pilaster apertures, another hook element extending from said siderail main wall proximate to and rearward of the fore end thereof, said another hook element pointing downward and being disposed in the same common plane with the aforesaid pair of hook elements which are laterally offset from and substantially parallel to the plane of the main wall, and a tongue element extending from and above said siderail main wall in vertically offset above-lying relation to said another book element and lying in a plane substantially perpendicular to the plane of the main wall with the plane of the tongue element substantially vertically bisecting said another hook element, said siderail being adapted for looking engagement to said pair of pilasters by first projecting said pair of book elements through an adjacent pair of apertures in one of said pilasters and locking the pair of books behind the pilaster front wall by end shifting the siderail, torsioning the siderail fore end to project the said tongue element through the slot portion of an aperture of the other pilaster and upward therebeyond behind the pilaster front wall, projecting the said another hook through the rectangular portion of the next lower aperture of the said other pilaster by releasing the torsion on the siderail fore end, and then depressing the fore end of the siderail to lock the said another hook behind the pilaster front wall.

-11. The apparatus according to claim 10 wherein the lateral offset of said pair of rear-wardly turned hook elements from said siderail main wall is substantially equal to'the thickness of the apertured pilaster wall through which said pair of hooks are projectable so that said pair of rearwardly turned hook elements pass closely behind a portion of the pilaster wall adjacent to the apertures therein when the siderail is end shifted to thereby position said pair of book elements and siderail body closely adjacent to and on opposite sides of the said pilaster wall portion.

12. The apparatus according to claim 11 wherein the vertical extent of each of said pair of rearwardly turned hook elements is substantially the same as the vertical extent of the rectangular portion of said pilasters apertures, and the horizontal extent of said another book is substantially the same as the horizontal extent of the rectangular portion of said pilasters apertures, whereby, when said siderail is installed to said pilasters it is horizontally immovable and the rear end thereof is vertically immovable.

References Cited in the file of this patent UNITED STATES PATENTS 2,686,704- Wolters Aug. 17, 1954 2,815,649 Di Angelus et al Dec. 10, 1957 2,883,253 Litman Apr. 21, 1959 

2. APPARATUS FOR SUPPORTING A TRAY OR SHELF WITHIN A CABINET AT A DESIRED ELEVATION, COMPRISING IN COMBINATION, A PAIR OF PARALLEL SPACED-APART VERTICALLY EXTENDING PILASTERS ADAPTED FOR SECUREMENT TO THE CABINET WALL AND HAVING APERTURES FORMED THROUGH THE PILASTER FRONT WALL AT REGULARLY SPACED INTERVALS ALONG THE VERTICAL LENGTH THEREOF, AND A HORIZONTALLY EXTENDING SIDERAIL LOCKABLE AT ITS FRONT AND REAR ENDS RESPECTIVELY TO A DIFFERENT ONE OF SAID PAIR OF PILASTERS BY FRONT AND REAR LOCKING MEANS ASSOCIATED WITH SAID SIDERAIL, SAID REAR LOCKING MEANS INCLUDING A PROJECTION ENGAGEABLE WITH ONE OF SAID PAIR OF PILASTERS THROUGH A FRONT WALL APERTURE THEREOF AND LOCKABLE TO SAID PILASTER SO ENGAGED BY SHIFTING SAID SIDERAIL LONGITUDINALLY ENDWISE, SAID FRONT LOCKING MEANS INCLUDING A PAIR OF PROJECTIONS ENGAGEABLE WITH THE OTHER OF SAID PAIR OF PILASTERS RESPECTIVELY THROUGH A PAIR OF FRONT WALL APERTURES THEREOF AND LOCKABLE TO SAID PILASTER SO ENGAGED BY (A) FIRST ROTATING THE SAID SIDERAIL ABOUT ITS LONGITUDINAL AXIS AND INSERTING ONE OF SAID PAIR OF PROJECTIONS THROUGH ONE OF SAID PAIR OF PILASTER FRONT WALL APERTURES TO THEREBY DISPOSE THE SAME PARTIALLY BEHIND THE PILASTER FRONT WALL, (B) THEN COUNTER-ROTATING THE SAID SIDERAIL ABOUT ITS LONGITUDINAL AXIS AND INSERTING THE OTHER OF SAID PAIR OF PROJECTIONS THROUGH THE OTHER OF SAID PAIR OF PILASTER FRONT WALL APERTURES, (C) AND VERTICALLY SHIFTING THE SIDERAIL FRONT END TO LOCK SAID PAIR OF PROJECTIONS TO THE PILASTER WITH WHICH THEY ARE ENGAGED. 